Onyx has been used for carving for centuries but it was particularly popular in the Art Deco era. It comes in several colors but black was particularly popular in jewelry, clocks, cigarette cases, compacts and many other items. Other popular colors were green and white.
It is formed of bands of chalcedony in alternating colors and is cryptocrystalline, consisting of fine inter-growths of the silica minerals quartz and moganite. Its bands are parallel to one another, as opposed to the more chaotic banding that often occurs in agates. Reference: Wikipedia
Below are some examples and price guides of Art Deco onyx items including a fob watch and an Art Deco jewel casket.
CHAUMET: ART DECO ONYX AND DIAMOND FOB WATCH, CIRCA 1925 The octagonal dial with Arabic numerals in a platinum case with engraved floral and foliate decoration and a cabochon crown, the reverse set with an onyx panel, accented by old brilliant and single-cut diamonds, suspended from a single-cut diamond brooch fitting mounted in white gold, via black ribbon, signed J. Chaumet, Paris London, maker’s marks JC, French assay mark, length 6.7cm
Sold for £ 4,845 inc. premium at Bonham’s in 2020
CARTIER ART DECO CIGARETTE BOX DIAMONDS, ONYX AND CORAL
METAL: platinum (950) DIAMONDS: rose cut diamonds for an approximate total weight of 0.8 – 1.0 carat CORAL: cabochon coral Onyx plates SIZE / DIMENSIONS: 9.0 x 6.3 x 1.2 cm DATE: circa 1927 SIGNATURE: Cartier BRANDS: French hallmarks for gold, numbered 02523 and 48098 GROSS WEIGHT: 87.48 g Accompanied by it’s Cartier-shaped case and pouch
Sold for EUR 20,000 at Christie’s in 2020
Pair of Art Deco Platinum, Diamond and Black Onyx Cufflinks and Two Studs, France The double-sided cuffinks of round black onyx, centering 4 old European-cut diamonds ap. .50 ct., encircled by rose-cut diamonds, the studs of similar motif, with gold fittings, with French assay marks, c. 1920.
Sold for $1,875 (includes buyer’s premium) at Doyle in 2020
AN ART DECO DIAMOND AND ONYX BROOCH, EARLY 20TH CENTURY of circular design, set with four principal old cut diamonds of 0.65, 0.64, 0.63 and 0.61 carats, within rows of single cut diamonds and step cut onyx, the diamonds all totalling 3.0-3.2 carats, unmarked, 3.3cm, 3.7g.
Sold for £1,700 at Elmwood’s in 2021
An Art Deco onyx, jewel casket with silver and enamel mounts, attributed to Lacloche Frères, French, circa 1930 rectangular, the mounts with black and red enamel motifs, black finial and four rectangular supports, stamped: Made in France, London import marks for Stockwell & Co, 1931
Sold for 5,250 GBP at Sotheby’s in 2017
Green Brazilian Onyx Electric art deco clock. Syncronhronous movement. Paper label still present.
Sold for $100 at Nest Egg Auctions in 2020
